City officials would have to hold community meetings and provide evidence that red light ticket cameras would make specific intersections safer before they could install the devices going forward under a plan that also would establish standard lengths for yellow lights across Chicago.

Ald. Tom Tunney, 44th, and Ald. Anthony Beale, 9th, want to require that all intersections in the city equipped with the cameras have so-called "countdown" pedestrian-control signals so people driving toward a green light could see how many seconds are left before it changes. The proposal would set yellow light lengths of at least 3.2 seconds. And it would require City Council approval of each camera location, giving aldermen who don't want the cameras in their neighborhoods a measure of say-so.

In addition, city officials would need to produce traffic studies estimating the safety impact of the cameras at intersections where they want to put them.

"We want to make sure red light camera installations are for public safety, and not the perceived revenue issues they have been," Tunney said.

Mayor Rahm Emanuel said he had not seen the ordinance, and he declined comment Wednesday on whether he thinks the proposed changes to the red light camera program are a good idea. If Emanuel doesn't back the plan, it has little chance of success.

The move comes after the Chicago Tribune reported last fall that the Emanuel administration quietly issued a new, shorter yellow light standard when the city began the transition from red light camera vendor Redflex Traffic Systems to Xerox State & Local Solutions in February 2014. The switch to a 2.9-second yellow came after the city had long set the standard length for yellow lights at three seconds.

Around $7.7 million in tickets were issued to motorists caught driving through signals with yellow lights that were at least 2.9 seconds long. The city later returned to a three-second yellow light standard.

Chicago's red light camera system grew to more than 350 cameras and has raised more than $500 million in $100 tickets since 2002. Tribune investigations beginning in 2012 have exposed corruption, failed oversight and inconsistent enforcement in the program.

Last month, the Tribune published a story in which researchers it hired to analyze the effects of the city's red light cameras found that at nearly half the intersections in the study, the cameras did nothing to make drivers safer and may have caused an increase in injury-related crashes.

"In order to put these in, we want to make sure we've done the right due diligence as far as the community's concerned and the intersections are concerned," Tunney said. "Because the data seems to be conflicting at times, based on some of the Tribune analysis. So we want to make sure there's a thorough study, make sure it's before they're put in, and not done afterward. And then we also want to make sure the alderman has control over their intersections, because it's our constituents that we have to respond to."